Meta: Support generating case-insensitive value-from-string methods

This also extracts the default parameters for generate_value_from_string
to a structure. This is just to make it cleaner to add new options.

Meta/Lagom/Tools/CodeGenerators/LibUnicode/GenerateUnicodeLocale.cpp

@@ -1077,7 +1077,11 @@ Optional<StringView> get_locale_@enum_snake@_mapping(StringView locale, StringVi
         for (auto const& alias : aliases)
             hashes.set(alias.key.hash(), alias.value);
 
-        generate_value_from_string(generator, "resolve_{}_alias"sv, s_string_index_type, enum_snake, move(hashes), "StringView"sv, "s_string_list[{}]"sv);
+        ValueFromStringOptions options {};
+        options.return_type = "StringView"sv;
+        options.return_format = "s_string_list[{}]"sv;
+
+        generate_value_from_string(generator, "resolve_{}_alias"sv, s_string_index_type, enum_snake, move(hashes), options);
     };
 
     append_from_string("Locale"sv, "locale"sv, locale_data.locales.keys(), locale_data.locale_aliases);

Meta/Lagom/Tools/CodeGenerators/LibUnicode/GeneratorUtil.h

@@ -293,15 +293,21 @@ struct HashValueComparator
 template<typename ValueType>
 using HashValueMap = HashMap<unsigned, ValueType>;
 
+struct ValueFromStringOptions {
+    Optional<StringView> return_type {};
+    StringView return_format { "{}"sv };
+    CaseSensitivity sensitivity { CaseSensitivity::CaseSensitive };
+};
+
 template<typename ValueType>
-void generate_value_from_string(SourceGenerator& generator, StringView method_name_format, StringView value_type, StringView value_name, HashValueMap<ValueType> hashes, Optional<StringView> return_type = {}, StringView return_format = "{}"sv)
+void generate_value_from_string(SourceGenerator& generator, StringView method_name_format, StringView value_type, StringView value_name, HashValueMap<ValueType> hashes, ValueFromStringOptions options = {})
 {
     ensure_from_string_types_are_generated(generator);
 
     generator.set("method_name", String::formatted(method_name_format, value_name));
     generator.set("value_type", value_type);
     generator.set("value_name", value_name);
-    generator.set("return_type", return_type.has_value() ? *return_type : value_type);
+    generator.set("return_type", options.return_type.has_value() ? *options.return_type : value_type);
     generator.set("size", String::number(hashes.size()));
 
     generator.append(R"~~~(
@@ -334,11 +340,23 @@ Optional<@return_type@> @method_name@(StringView key)
         }
     }
 
-    generator.set("return_statement", String::formatted(return_format, "value->value"sv));
+    generator.set("return_statement", String::formatted(options.return_format, "value->value"sv));
     generator.append(R"~~~(
     } };
+)~~~");
+
+    if (options.sensitivity == CaseSensitivity::CaseSensitive) {
+        generator.append(R"~~~(
+    auto hash = key.hash();
+)~~~");
+    } else {
+        generator.append(R"~~~(
+    auto hash = CaseInsensitiveStringViewTraits::hash(key);
+)~~~");
+    }
 
-    if (auto const* value = binary_search(hash_pairs, key.hash(), nullptr, HashValueComparator<@value_type@> {}))
+    generator.append(R"~~~(
+    if (auto const* value = binary_search(hash_pairs, hash, nullptr, HashValueComparator<@value_type@> {}))
         return @return_statement@;
     return {};
 }